Pacemaker Implantation in Cats

A pacemaker continuously monitors the heart’s rhythm and sends electric impulses to the heart’s muscle to make the heart contract when it is pulsing irregularly or too slow. The pacemaker itself consists of pacing leads and a pulse generator. The generator of the pacemaker is a small metal case that is no larger than a silver dollar, with a small computer and battery inside. The pacing leads are thin wires that carry electricity from the pulse generator to the heart. The pulse generator and the pacing leads work together to increase the heart rate, delivering appropriately oxygenated blood to the body. A pacemaker is placed in the feline by a licensed veterinary cardiologist and veterinary surgeon. 

The veterinary cardiologist will evaluate the patient for proper pacemaker implantation. Ideal feline patients will have minimal structural heart disease, free of intracardiac tumors and other life-threatening health conditions. The feline patient will have a complete pre-implant evaluation including an abdominal ultrasound, tick serology, blood pressure evaluation, a 6-lead EKG (electrocardiogram), abdominal and thoracic radiographs, a urinalysis, as well as blood work. 

A pacemaker implant can be placed in one of two ways; transvenous pacemaker implantations or epicardial pacemaker implantations. Transvenous pacemaker implantations are reserved for dogs as their veins support the pacemaker lead running down their jugular vein and attaching the generator to the neck muscle. Cats on the other hand require epicardial pacemaker implantations, which allows the generator to be placed within the abdomen rather than the neck. 

The veterinary cardiologist and the veterinary surgeon work together to perform an epicardial pacemaker implantation in the pre-approved feline. A step-by-step procedure is listed below: 

• The feline will be anesthetized with a pre-anesthetic combined with a pre-antibiotic to prevent infection and a pain medication. 
• The feline will have an esophageal tube placed and supplementary oxygen will be given. 
• Vital signs will be checked and gas anesthetic will be administered. 
• An incision will be made though the cat’s diaphragm to place the generator. The use of an ultrasonic device will likely be used to assist for proper placement. 
• The lead to the generator is attached to the apex of the heart and the lead is then run through a large vein where it meets the right side of the heart. 
• The tip of the lead is then situated in the right ventricular apex, where it will connect to the inside of the heart’s muscle. 
• The pacemaker will then be activated to deliver pulses of electricity down the lead to the heart where it will stimulate a contraction. 
• The incision site will then be stitched closed and the feline patient will be sent to the recovery area. 

Patients will remain in veterinary care overnight to ensure the pacemaker is working properly. The procedure of implanting the pacemaker itself should take approximately 1-2 hours to complete. 

The prognosis for patients that have had a successful pacemaker implantation is generally good. The majority of patients live several years with their pacemakers with no adverse side effects. 

After the procedure, abdominal and chest radiographs will be taken to ensure proper placement of the pacemaker. The patient will be hospitalized overnight for continuous heart rate monitoring, which will ensure the pacemaker is functioning properly. The patient will be allowed to return home wearing a bandage over the incision for the next 7-10 days. Activity restrictions will be put into effect for 4-6 weeks after surgery and medications are to be administered as directed. 

Periodic follow-up examinations are to be expected, which usually coincide with interrogation of the pacemaker generator. The patient will not need to be anesthetized for interrogation as the pacemaker can be reached through an external magnet and computer. Interrogation of the pacemaker usually takes place every six months. 

The estimated cost of pacemaker implantation in cats is roughly $3,000 to $3,500. The total cost includes the exam, echocardiogram, radiographs, procedure, pacemaker device and the overnight costs of placing the pacemaker in the feline. 

Now that your cat has a pacemaker implant, you will need to inform the veterinarian of this implanted device at every veterinary visit. Computed tomography (CT) scans and magnetic resonance imagining (MRI) can interfere with the functionality of the pacemaker, so ensure your veterinarian is aware of your cat’s device. Venipuncture of the vein that holds the pacemaker lead should be avoided as this action of drawing blood can damage the lead.  

Many felines that require pacemakers are of old age and it is the act of aging that has lead them to need a pacemaker. Other feline heart abnormalities might be able to be prevented with proper diet and exercise, but some felines have a genetic tendency to develop heart arrhythmias.